diff --git a/repos/ports/src/app/seoul/disk.cc b/repos/ports/src/app/seoul/disk.cc
index 9f073f562..81f15f54d 100644
--- a/repos/ports/src/app/seoul/disk.cc
+++ b/repos/ports/src/app/seoul/disk.cc
@@ -140,7 +140,7 @@ void Seoul::Disk::handle_disk(unsigned disknr)
 		}
  
 		{
-			Genode::Lock::Guard lock_guard(_alloc_lock);
+			Genode::Mutex::Guard guard(_alloc_mutex);
 			source->release_packet(packet);
 		}
 		destroy(&_tslab_msg, msg);
@@ -235,7 +235,7 @@ void Seoul::Disk::check_restart()
 		if (restarted) {
 			destroy(&_tslab_avl, obj);
 		} else {
-			Genode::Lock::Guard lock_guard(_alloc_lock);
+			Genode::Mutex::Guard guard(_alloc_mutex);
 			_restart_msg.insert(obj);
 		}
 	}
@@ -254,7 +254,7 @@ bool Seoul::Disk::restart(struct disk_session const &disk,
 	Block::Packet_descriptor packet;
 
 	try {
-		Genode::Lock::Guard lock_guard(_alloc_lock);
+		Genode::Mutex::Guard guard(_alloc_mutex);
 
 		packet = Block::Packet_descriptor(
 			disk.blk_con->alloc_packet(blocks * blk_size),
@@ -311,7 +311,7 @@ bool Seoul::Disk::execute(bool const write, struct disk_session const &disk,
 	char * source_addr          = nullptr;
 
 	try {
-		Genode::Lock::Guard lock_guard(_alloc_lock);
+		Genode::Mutex::Guard guard(_alloc_mutex);
 
 		packet = Block::Packet_descriptor(
 			disk.blk_con->alloc_packet(blocks * blk_size),
@@ -371,7 +371,7 @@ bool Seoul::Disk::execute(bool const write, struct disk_session const &disk,
 				source->submit_packet(packet);
 			else {
 				/* failed packet allocation, restart at later point in time */
-				Genode::Lock::Guard lock_guard(_alloc_lock);
+				Genode::Mutex::Guard guard(_alloc_mutex);
 				_restart_msg.insert(new (&_tslab_avl) Avl_entry(source_addr,
 				                                                msg_cpy));
 			}
@@ -382,7 +382,7 @@ bool Seoul::Disk::execute(bool const write, struct disk_session const &disk,
 		destroy(disk_heap(), msg_cpy->dma);
 		destroy(&_tslab_msg, msg_cpy);
 		if (source_addr) {
-			Genode::Lock::Guard lock_guard(_alloc_lock);
+			Genode::Mutex::Guard guard(_alloc_mutex);
 			source->release_packet(packet);
 		}
 		return false;
@@ -415,7 +415,7 @@ bool Seoul::Disk::execute(bool const write, struct disk_session const &disk,
 	} else {
 		destroy(&_tslab_msg, msg_cpy);
 
-		Genode::Lock::Guard lock_guard(_alloc_lock);
+		Genode::Mutex::Guard guard(_alloc_mutex);
 		source->release_packet(packet);
 	}
 	return ok;
diff --git a/repos/ports/src/app/seoul/disk.h b/repos/ports/src/app/seoul/disk.h
index 24cc5232e..b35e6376f 100644
--- a/repos/ports/src/app/seoul/disk.h
+++ b/repos/ports/src/app/seoul/disk.h
@@ -128,8 +128,8 @@ class Seoul::Disk : public StaticReceiver<Seoul::Disk>
 
 		Genode::Avl_tree<Avl_entry> _lookup_msg  { };
 		Genode::Avl_tree<Avl_entry> _restart_msg { };
-		/* _alloc_lock protects both lists + alloc_packet/release_packet !!! */
-		Genode::Lock                _alloc_lock  { };
+		/* _alloc_mutex protects both lists + alloc_packet/release_packet !!! */
+		Genode::Mutex               _alloc_mutex { };
 
 		/*
 		 * Noncopyable
@@ -167,7 +167,7 @@ class Seoul::Disk : public StaticReceiver<Seoul::Disk>
 		Avl_entry * lookup_and_remove(Genode::Avl_tree<Avl_entry> &tree,
 		                              void * specific_obj = nullptr)
 		{
-			Genode::Lock::Guard lock_guard(_alloc_lock);
+			Genode::Mutex::Guard guard(_alloc_mutex);
 
 			Avl_entry * obj = tree.first();
 			if (obj && specific_obj)
diff --git a/repos/ports/src/app/seoul/timeout_late.h b/repos/ports/src/app/seoul/timeout_late.h
index d097aad45..0ebe45e60 100644
--- a/repos/ports/src/app/seoul/timeout_late.h
+++ b/repos/ports/src/app/seoul/timeout_late.h
@@ -36,8 +36,8 @@ class Late_timeout
 
 	private:
 
-		Genode::Lock _lock   { };
-		Remote       _remote { };
+		Genode::Mutex _mutex  { };
+		Remote        _remote { };
 
 	public:
 
@@ -45,7 +45,7 @@ class Late_timeout
 
 		void timeout(Clock &clock, MessageTimer const &msg)
 		{
-			Genode::Lock_guard<Genode::Lock> guard(_lock);
+			Genode::Mutex::Guard guard(_mutex);
 
 			Genode::uint64_t const now = clock.time();
 
@@ -58,7 +58,7 @@ class Late_timeout
 
 		Remote reset()
 		{
-			Genode::Lock_guard<Genode::Lock> guard(_lock);
+			Genode::Mutex::Guard guard(_mutex);
 
 			Remote last = _remote;